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Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 829 records · Page 46Linked to original sources
PubMed1987

Pharmacological characterization of spinal alpha adrenoceptors related to blood pressure control in rats.

The effects of various alpha adrenoceptor agonists and antagonists injected into the spinal subarachnoid space on blood pressure and heart rate were investigated in pentobarbital-anesthetized male rats. A dose-dependent decrease in blood pressure and heart rate was induced by intrathecal injections of clonidine (0.3-3 micrograms), at the T6-T7 level. Guanabenz (3-30 micrograms) and an azepine derivative B-HT 920 (1-3 micrograms) also reduced blood pressure and heart rate. In contrast, an imidazolidine derivative St 587 (10 micrograms) was ineffective. The clonidine-induced hypotensive effect was antagonized by yohimbine but not by prazosin. Yohimbine (3-10 micrograms) alone caused an increase in blood pressure and heart rate while only a weak hypotenion occurred with prazosin (10 micrograms). Pretreatment with intrathecal 6-hydroxydopamine (50 micrograms X 2) did not impair the hypotensive action of clonidine (1 microgram) whereas the hypertensive effect of yohimbine was reduced markedly by this treatment. When injected i.v. or intrathecally at the C1-C2 level, clonidine (1 microgram) produced only a slight decrease in blood pressure. It is concluded that, in rat spinal cord, alpha-2 adrenoceptors located postsynaptically are involved in blood pressure control. Endogenous catecholamines, especially norepinephrine in the spinal cord seem to activate tonically the alpha-2 adrenoceptors.

Adrenergic alpha-Antagonists↗
PubMed1987

Comparative study of phenothiazine derivatives on monoamine metabolism--direct correlation between the concentrations of drugs and monoamine metabolites in the brain.

The pharmacokinetics (distribution and elimination) and pharmacodynamics (biochemical effects on monoamine systems) of phenothiazines including the novel compound, E-0663 (10-[3-(3-hydroxypyrrolidinyl)-propyl]-2-trifluoromethyl phenothiazine), in the central nervous system were investigated concurrently in mice using high-performance liquid chromatography with electrochemical detection. The elimination rate of E-0663 from the brain was longer than that of the classical compounds, chlorpromazine, perphenazine and triflupromazine. The phenothiazine (0.01-100 mumol/kg i.v.) increased the metabolites of catecholamines. Direct correlation analysis was applied to the intracerebral concentrations of the drugs and monoamine-related substances. Significant correlations were observed between the concentrations of drugs and dopamine metabolites (3,4-dihydroxyphenylacetic acid and homovanillic acid). The relative potency of the drugs for the effect on the extraneuronal process was promethazine less than chlorpromazine less than E-0663 less than triflupromazine less than perphenazine by covariance analysis. On the other hand, noradrenaline metabolite (3-methoxy-4-hydroxyphenylethylene glycol) also revealed a significant correlation, and the potency was highest in the case of E-0663. These results suggest that E-0663 possessed different pharmacokinetic profiles and a different spectrum in its action on monoamine metabolism from classical phenothiazines. The method described here is simple for comparing the real potency and is useful as a new approach in the biochemical pharmacology of centrally acting drugs.

Animals↗
PubMed1987

[Rhabdomyosarcoma of the prostate: report of a case and review of the literature].

Rhabdomyosarcoma of the prostate is a rare tumor and its prognosis is extremely poor. However, the survival rate has been gradually improved by using combined chemotherapy. A 17-year-old man with the chief complaint of dysuria was referred to our hospital on April 7, 1986. Prostatic needle biopsy was performed and pathological diagnosis was rhabdomyosarcoma of the prostate. The patient was given preoperative combined chemotherapy consisting of actinomycin D and cyclophosphamide. Total cystoprostaurethrectomy and ileal conduit were performed on April 30, 1986. He underwent postoperative combined chemotherapy (vincristine, actinomycin D, cyclophosphamide). He is well 13 months after his initial symptoms and is clinically free of tumor 12 months postoperatively. Forty-two cases of rhabdomyosarcoma of the prostate including our case were collected from the Japanese literature and reviewed with respect to the multimodal treatment and prognosis.

Adolescent↗
PubMed1987

[A study of 114 cases of urinary tract injury].

In 11 years between January, 1974 and December, 1984 114 patients (92 males and 22 females) were admitted to our departments for urologic injuries. As there were four patients with multiple injuries (both kidneys 1, kidney and ureter 1, kidney and urethra 1, and bladder and urethra 1), the number of cases with kidney, ureter, bladder and urethral injuries were 76 (64%), 33 (28%), 6 (5%) and 3 (3%), respectively. The most frequent incidence was in the second decade. Out of the 75 cases of renal injuries there were 42 cases (56%) of contusions, 21 (28%) of lacerations, 7 (9.3%) of ruptures and 5 (6.7%) of pedicle injuries. Only 14 cases (18.7%) were treated surgically, namely six by nephrectomy and eight by a conservative approach (suture 1, drainage 3, partial nephrectomy 3 and pyeloplasty 1). Of the 3 cases of ureteral injuries all cases were treated surgically. Of the 6 cases of bladder injuries four cases were treated surgically. Of the 33 cases of urethral injuries 10 cases were complicated by fractures of the pelvis. Twenty three cases (74%) were treated surgically.

Accidents, Traffic↗
PubMed1987

Studies on GABAergic mechanisms responsible for cardiovascular regulation in the rostral ventrolateral medulla of the rat.

Cardiovascular effects of chemical stimulation of the rostral ventrolateral medulla were studied in pentobarbital-anesthetized, paralyzed rats to examine the medullary GABAergic mechanisms responsible for cardiovascular regulation. Bilateral microinjections of 3-mercaptopropionic acid (10 micrograms), an inhibitor of gamma-aminobutyric acid (GABA) synthesis, into the ventrolateral medulla produced an increase in blood pressure and heart rate. Unilateral microinjection of nipecotic acid (3 micrograms), a reuptake inhibitor of GABA, elicited a fall in arterial pressure and heart rate. Bilateral microinjections of bicuculline (100 pmol), a GABA antagonist, into the ventrolateral medulla produced a sustained increase in arterial pressure and heart rate and, in addition, inhibited the hypotensive action induced by veratrine (0.3 mg/kg, i.v.). Lesioning of the rat nucleus tractus solitarii did not alter GABA content in the rostral ventrolateral medulla. These results support the hypothesis that in the rostral ventrolateral medulla, there exist GABAergic mechanisms involved in cardiovascular regulation. It seems unlikely that the GABAergic mechanisms originate mainly from neurons in the nucleus tractus solitarii.

3-Mercaptopropionic Acid↗
PubMed1987

[A case of giant hydronephrosis with renal pelvic calcification].

A 26-year-old man had asymptomatic macroscopic hematuria. A left hydronephrotic sac outlined with a thin curvilinear shadow of calcium deposition was found in a plain film and stenosis at the ureteropelvic junction (UPJ) in a retrograde pyelogram. Left nephrectomy was performed and the fluid content was 1330 ml. Histologic examination showed subepithelial calcification of the renal pelvis and fibrous proliferation at the UPJ.

Adult↗
PubMed1987

[Evaluation of preoperative bladder tumor staging].

Twenty-eight out of 90 patients with bladder tumor seen from 1979 to 1982 were examined by CT, pelvic angiography, cystography and bimanual digital palpation for staging diagnosis preoperatively. Twenty-two patients underwent total cystectomy, and the other 6 patients underwent partial cystectomy. Preoperative staging (T) and postoperative histopathological staging (pT) were compared to define the diagnostic accuracy. The accuracy rate with CT was 20.0%, that with pelvic angiography, 29.4%, that with cystography 33.3%, and that with bimanual digital palpation 47.1%. Digital palpation had a better diagnostic accuracy rather than other examinations.

Aged↗
PubMed1987

[Clinical experience with cefbuperazone in complicated urinary tract infection].

Cefbuperazone (CBPZ) was administered to inpatients with complicated urinary tract infections (UTI) at our department. Clinical efficacy and safety were evaluated in 22 chronic cases by the criteria for evaluation of clinical of antimicrobial agents on urinary tract infection. Overall clinical efficacy was excellent in 8 cases, moderate in 9 cases and poor in 5 cases with an effectiveness rate of 77%. Twenty-four of the 34 strains isolated from the patients were eradicated and eradication rate was 71%. Neither subjective nor objective adverse reactions were observed. Abnormal changes in laboratory tests were found in 9 patients, but were probably not related to CBPZ administration. Judging from these results, CBPZ is considered to be an effective and safe antibacterial for the treatment of complicated UTI.

Adult↗
PubMed1987

[Effect of selective intra-arterial infusion of OK-432 against renal cell cancers].

In 8 cases of operable renal cancer, selective intraarterial infusion of the streptococcal preparation, OK-432 was performed and its cytocidal effects on the surgical specimens, which were removed on the 8th day after infusion, were investigated histopathologically with immunological parameters of the peripheral blood. The histopathological study revealed a high grade of sinus histiocytosis of the renal pedicle lymph nodes, but the anti-tumor effect on renal tumors was not so marked in any of the 8 cases. OK-Ia-positive lymphoid cells of peripheral blood were increased significantly and Con-A stimulation index of blastogenesis was lowered without any change in the PHA stimulation index after the OK-432 infusion. No serious complications of the selective intraarterial infusion were experienced except for high fever (less than 38 degrees C). In conclusion, OK-432 selective intraarterial infusion was an effective method for improving regional and systemic immunoactivity, but the cytocidal effect against tumor cells could not be confirmed histopathologically.

Aged↗
PubMed1986

Biphasic actions of L-DOPA on the release of endogenous dopamine via presynaptic receptors in rat striatal slices.

In rat striatal slices, 30 nM of L-DOPA increased the impulse (5 Hz)-evoked release of dopamine (DA), without increasing the spontaneous release and tissue content of DA. The minimum dose required to increase spontaneous DA release was 0.1 microM and the dose which led to an accumulation of DA was 100 microM. In the presence of NSD-1055, a DOPA-decarboxylase inhibitor, L-DOPA-induced increases in spontaneous DA release were prevented and L-DOPA produced dual actions on the evoked release of DA, a stereoselective propranolol-sensitive increase at 30 nM and a stereoselective sulpiride-sensitive decrease at 1 microM. L-DOPA produces dual presynaptic regulatory actions on DA release, via facilitatory beta-adrenoceptors at 30 nM and inhibitory DA receptors at 1 microM. The primary action of L-DOPA appears to be the facilitation of release of DA rather than the conversion to DA.

Animals↗
PubMed1986

Diminished alpha 2-adrenoceptor-mediated modulation of noradrenergic neurotransmission in the posterior hypothalamus of spontaneously hypertensive rats.

An azepine derivative, 6-allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo-[4,5-d]-azepine (B-HT 920; 100 nM), inhibited the evoked noradrenaline release from slices of rat posterior hypothalamus, and yohimbine (100 nM) potentiated the release from slices of rat anterior and posterior hypothalamus. In the posterior hypothalamus of 4- and 15-16-week-old spontaneously hypertensive rats (SHRs), as compared with age-matched Wistar-Kyoto rats (WKYs), the inhibitory effect of B-HT 920 and the facilitatory effect of yohimbine were decreased. In the anterior hypothalamus there was no significant difference in the yohimbine effect between WKYs and SHRs, at either age. It is concluded that alpha 2-adrenoceptor-mediated autoinhibition of noradrenergic neurotransmission is diminished in the posterior hypothalamus of SHRs.

Animals↗